#include<bits/stdc++.h>
#define y1 Y1
#define fi first
#define endl "\n"
#define se second
#define PI acos(-1)
#define int long long
#define pb(x) push_back(x)
#define PII pair<int, int>
#define Yes cout << "Yes\n";
#define No cout << "No\n";
#define YES cout << "YES\n";
#define NO cout << "NO\n";
#define _for(i, a, b) for(int i = a; i <= b; ++i)
#define IOS ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
using namespace std;

const int N = 2e5 + 10;
int a[N];
int n, m;
string s;
unordered_map<int, int>mp;
 
signed main() {
	IOS;
	int t;
	cin >> t;
	while(t--) {
		mp.clear();
		cin >> n;
		_for(i, 1, n) {
			int x;
			cin >> x;
			mp[x]++;
			if(mp[x] == 1) {
				cout << x << ' ';
			}
		}
		cout << endl;
	}
	return 0;
}

